Compressor



Maf. 27, 1923. 1g450-,1122

J. TWARDOWSKY COMPRES SOR Filed pt. 50, 1921 Patente'd Maf. 27, 1923.

UNITED STATES 1,450,122 PATENT OFFICE.

JOHN TWARDOWSKY, OF CHICAGO, ILLINOIS, ASSIGNOR, BY MESNE ASSIGNMENTS, T0 UNIVERSE CORPORATION, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

COMPRESSOR.

Application filed September 30, 1921.

To all whom it may concern:

Be it known that I, JOHN TWARDOWSKY, citizen of Russia, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in a Compressor; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will" enable others skilled in the art to which it appertains to make and use the same.

'My invention relates to compressors and in its general objects aims to provide simple, effective and entirely automatic mea-ns for separat-ing the compressed fluid from any lubricating oil which has been carried past the compressor proper, for returning such separated oil to the oil storage chamber, and for maintaining a desirable pressure back of the piston of the compressor.

In operating fluid compressors, such as those forming parts of mechanical refrig- Aerating systems, it is highly important that an ample supply of lubricant should be provided for the piston or other movable compressing member, so as to avoid the necessity of requiring attention to these parts in order to prevent undue wear. For this purpose it has been customary in fluid compressors of the piston type to employ the crank casing as an oil storage receptacle out of which oil is splashed against the piston by the cra-nk and the connecting rod. In practice, some of this oil will forma film on the bore of the cylinder during the inta-ke stroke of the piston and parts of the oil will then be carried with the compressed fluid into the discharge chamber. If left intermiXed with the compressed fluid, the oil will interfere with the proper operation of the expansion portion of the system and of the means for controlling the expansion. hence it is highly advisable that the entrained oil should be separated from the fluid before the latter is discharged into the piping of the system. It is also advisable for the sake of economy that this oil should be returned to the crank casing so as to be used over again.

So also, it is desirable in compressors of this general type to maintain some pressure continuously in the crank casing, so that the com ressing stroke of the piston will not pro uce a partial vacuum in the crank casing, as such a partial vacuum would tend to draw air through the bearings into this Serial No. 504,526.

casing. This is particularly true with mechanical refrigerating systems using ethyl chloride, methyl chloride or sulphur dioxide as the operating fluid.

In the copending application #4:73781 for a patent on a compressor as filed May 31, 1921 by Hanson and Twardowsky, means have been shown for separating the entrained oil from the compressed fluid and for permitting the pressure of the latter to discharge the separated oil into the crank casing at the end of each compression stroke of the piston through a return passage controlled partly by a needle valve and partly by the piston. Tith thearrangement there disclosed, the return passage is opened to some extent with everyY reciprocation of the piston. regardless of the pressure in the crank casing. Consequently, it is dillicult to maintain a proper adjustment of the valve for this purpose, as an unduly restricted opening will hold back the oil, while an excessive opening may permit some of the compressed fluid to enter the crank casing under substantially full pressure. thereby causing an undue back pressure in the crank casing and wasting the effect of some of the compressing. My present invention aims to overcome these difliculties and in general aims to provide simple. easily adjusted and entirely automatic means for feeding the separated oil back into the crank casing and vfor maintaining a desirable amount of Huid pressurev in the said casing. It also aims to provide simple and easily'. manipulated means for adjusting the pressure thus maintained in the crank casing` and desirably aims to provide simple means for employing a balanced valve for this purpose. Stil further and more detailed objects will appear from the following specification and from the accompanying drawings, in which- Fig. 1 is a central and vertical section through a compressor equipped w1th my invention. Fig. 2 is afragmentary horizontal section f taken along the correspondingly numbered line in Fig. 1 and showing a portion of the `oil return passage between the oil separator and the diaphragm-controlled needle valve which automatically governs the returnmg of the oil.

In the embodiment of the drawings, I am showing my invention as applied to a .compressor of the simple piston and cylinder l type, in which the compressing is effected by a piston 1 reciprocated in a cylinder 2 by a pitman 3 connected to a continuously rotating crank 4. I am also showing the discharge from the cylinder as controlled by a metal plate 5 normally pressed into its closure position by a spring 6 and forming a ycrank casing 11, I interpose a return duct including a diaphragm casing 12 and a pipe 23 leading from the. latter to the crank casing. This diaphragm casing is desirably .bolted to the bottom of the separator casing and desirably has a vertical bore 13 connecting the separator chamber with the interior of the diaphragm casing. 4Slidably mounted in the bore 13 isa needle valve comprising a stem 14 and a tapering tip 15, the said tip having a seating portion tapered to correspond to the taperv of a seat 16 towards whlch seat the valve is continuously urged by a spring 17. The stern' 14 of the needle valve is desirably hollow so as to partly house the spring 17 and. has side portions cut away (as for example after the manner shown in Fig. 2) to afford passages through which oil may fiow down the sides of the bore 13 from the separatorv chamber 8 to the outlet into the diaphragm casing which outlet is v controlled by the conical shoulder ofthe needle valve.

While continuously urged downward by the spring 17 the needle valve is also urged upward both by aspring 18 in the lowerf part of the diaphragm casing and by any excess of pressure under the diaphragm 19 over that pressin against the top of the said diaphra m. or these latter purposes,

. I `desirably asten vthe diaphragm 18 to an upper pressure plate 20 which is recessed for engaging the extreme lower end of the needle valve, and I also fasten the diaphragm to a lower pressure plate 21 arranged for receiving the upward thrust of the spring 18. Then I clamp the peripheral portion of the diaphragm rmly and substantially air-tight between the flanges of the casing 12 so as to leave the central portion of the diaphragm free to vbe flexed upwardly or downwardly. I also 'provide suitable means, such as an inlet 22, for connecting the lower povtionfof the diaphragm casing with the outer air. K

Thus arranged. it will be obvious from Fig. 1 that the diaphragm is continuously urged upward bythe combined pressure of amount.

the spring 18 and the prevailing air pressure outside of the apparatus, while it is pressed downward by the combined pressure of the spring 17 and of the fluid in the upper portion of the diaphragm casing. As this upper portion is connected by the tube 13 with the interior of the crank casing, the pressure in it will respond to that in the crank casing. Consequently, if the arrangement as described is so adjusted that the valve is substantially balanced with a predetermined difference in pressure between the outer air and the interior of the crank casing, a reduction of pressure within the crank casing will permit the air pressure under the diaphragm v-to raise the latter, therebypermitting oil to be forced through the bore 13 and the pipe 23 by the pressure ofthe compressed fluid in the separator chamber 8. However, as soon as the resulting action raises the pressure within the crank casing sufficiently to overcome the distortion of the diaphragm which had opened the valve, the diaphragm will be flexed back to its normal position b-y the action of the spring 17, thereby closing the needle valve and shutting off the return connection between the separator chamber 8 and the crank casing.

To provide the delicate adjustment needed for this purpose, I desirably interpose an adjusting screw 24 between the bottom of the diaphragm casing and a pressure plate 25 which receives the downward thrust of the spring 18. By turning this screw 24 (which is normally locked in position by a nut 26) I can readily adjust the effective action of the spring 18 so as to have the needle valve opened only when the pressure in the crank casing drops below a given When thus adjusted, the action is entirely automatic, requiring no attention whatever on the part of the user.

However, while I have illustrated and described my invention as employed in connection with a certain type of compressor and as including certain desirable details of construction` I do not wish to be limited to this particular use of the same, nor to the details thus disclosed, it being obvious that the same might be modified in many ways without departing from the spirit of my invention or from the appended claims.

I claim as my invention:

1. In a compressor having an oil storing casing, an oil separator interposed in its discharge passage, and means responsive to a predetermined pressureA difference between the outer air and the interior of the said casing for forcing the separated oil into the y said casing.

compressor, and means responsive to a predetermined reduction in pressure in the crank casing for forcing oil from the separator into the crank casing.

3. In a compressor of the piston and cylinder type, a substantially airtight crank cas-ing serving also as an oil storage receptacle, an oil separator interposed in the discharge passage of the compressor,a11d means responsive to a predetermined difference between tl e outer air and the interior of the crank casing for forcing oil from the separator into the crank casing.

4. In a compressor of the piston and cylinder type. a substantially airtight crank casv ingl serving also as an oil storage receptacle,

an oil separator interposed in the discharge passage of the compressor, means responsive to a predetermined pressure difference between the outer air and thel interior of the crank casing for forcing oil from the separator into the crank casing, and means operable from outside the aforesaid me-ans for adjusting the. pressure ditference to which the latter respond.

ln a. compressor of the piston and cylinder type, a crank casing serving also as an oil storage receptacle. an oil separator interposed in the discharge passage of the compressor. a passagethrough which oil may be returned to the crank casing from the separator by the pressure ot' tluid in the latter. and means responsive to a predetermined diti'erence in pressure between the outer air and the interior of the crank casing for controlling the said passage.

G. ln a compressor ot' the piston and cylinder type. a crank casing serving also as an oil storage receptacle, an oil separator interposed in the discharge passage of the compressor. an oil return passage connecting the separator with the crank casing, a valve controlling the said return passage, and means responsive in action to variations in pressure in the crank casing for moving the valve.

- 7. Mechanism as per claim 6. in which the said means comprises a diaphragm having its opposite sides respectively subject to external air pressure and to the pressure within the crank casing.

8. Mechanism as per claim 6, in which the said means comprises a diaphragm having its opposite sides respectively subject to external air pressure and to the pressure within the crank casing, and adjustable springr means also acting on the diaphragm.

9. Mechanism as per claim 6, in which the said means comprises a diaphragm having its opposite sides respectively subject to external air pressure and to the pressure within the crank casing, a pair of opposed springs also acting on the vdiaphragm and means for adjusting the action of the springs.

10. Mechanism as per claim 6, in which the said means comprises a diaphragm having its opposite sides respectively subject to external air pressure and to the pressure within the crank casino*` a pair of opposed springs also acting on the diaphragm, and screw means adjustable from outside the valve for receiving the thrust of one of the springs.

Signed at Chicago. Illinois, September 17th. 1921.

JOHN TWARDOWSKY. 

